Particle size analyzer

Fig. 11. Particle size analyzer based on ultrasonic spectroscopy where DSP = digital signal processor, and RS 232 is a standard serial connection that allows...

Fig. 12. Schematic representation of the Galai particle size analyzer showing both the laser-based time-of-flight sizing equipment and the television camera...

The wavelength of 632.8 nm of the He-Ne laser is generally used in laser particle-size analyzers. 

The particle size analyzer, based on laser light diffraction, consists of a laser source, beam expander, collector lens, and detector (Fig. ] 3.45). The detector contains light diodes arranged to form a radial diode-array detector. The particle sample to be measured can be blown across the laser beam (dry sample), or it can be circulated via a measurement cell in a liquid suspension. In the latter case, the beam is direaed through the transparent cell. 

M.S.A.-WHitby Particle Size. Analyzer Data for Ammonium Nitrate. ... 

For the particle size measurements of boron and barium dichromate, components of pyrotechnic delay compns, Freeman (Ref 46) evaluated the MSA. Particle Size Analyzer versus microscopy, gravitational liq sedimentation,... 

Fig. 1 Schematic diagram of experimental apparatus Co.) and carbon particle size analyzer(LS230, COULTER Co.).

The morphology of the carbon was characterized by SEM and the particle size was determined by particle size analyzer. Figure 4 shows the SEM images of the carbon black. It was observed that the carbon black particles exhibit a sphere particle with nano-sized diameter. 

For accurate determination of the particle size, the particle size analyzer was used and particle sizes of carbons sjmthesized are compared with commercial carbon black (N700 and N800, KCB) in Table 2. It was confirmed from particle size analysis that particle size of carbon increased with increase of methane flow rate, as also appeared from SEM analysis. 

Table 2 Size of carbon black by particle size analyzer...

In order to generate proper size distribution of graphite powder, the milling parameters are adjusted. Changes in particle size distributions for the end-products are controlled with laser particle size analyzers (example Microtrac-XlOO, of Microtrac, Inc., Montgomeryville, PA, USA). 

The Microtrac-XlOO (a laser particle size analyzer) was used to determine the size distribution of the powder. The method is based on a liquid mode of operation, that is before laser scanning, the powder is added to a solution of deionized water, containing a surfactant. 

It must also be emphasized that the major mass of a heterodispersed aerosol may be contained in a few relatively large particles, since the mass of a particle is proportional to the cube of its diameter. Therefore, the particle-size distribution and the concentration of the drug particles in the exposure atmosphere should be sampled using a cascade impactor or membrane filter sampling technique, monitored using an optical or laser particle-size analyzer, and analyzed using optical or electron microscopy techniques. 

The development and refinement of population balance techniques for the description of the behavior of laboratory and industrial crystallizers led to the belief that with accurate values for the crystal growth and nucleation kinetics, a simple MSMPR type crystallizer could be accurately modelled in terms of its CSD. Unfortunately, accurate measurement of the CSD with laser light scattering particle size analyzers (especially of the small particles) has revealed that this is not true. In mar cases the CSD data obtained from steady state operation of a MSMPR crystallizer is not a straight line as expected but curves upward (1. 32. 33V This indicates more small particles than predicted... 

The fresh and spent catalysts were characterized with the physisorption/chemisorption instrument Sorptometer 1900 (Carlo Erba instruments) in order to detect loss of surface area and pore volume. The specific surface area was calculated based on Dubinin-Radushkevich equation. Furthermore thermogravimetric analysis (TGA) of the fresh and used catalysts were performed with a Mettler Toledo TGA/SDTA 851e instrument in synthetic air. The mean particle size and the metal dispersion was measured with a Malvern 2600 particle size analyzer and Autochem 2910 apparatus (by a CO chemisorption technique), respectively. 

The particle size distribution of each powder was determined using a Sympatec Helos/ Rodos laser diffraction particle size analyzer (Sympatec Inc., Princeton, New Jersey, U.S.A.) with dry powder dispersion capability. The powder dispersion pressure was varied between 0.5 and 2.0 bar (depending on the tendency for agglomeration) with direct feed into the dispersion funnel. The optical concentration was maintained in the range of 5% to 20%. The mean value of duplicate determinations is reported. 

EXAMPLE 2.2 Use of the Sedimentation Equation for Particle Size Determination. A titanium dioxide pigment of density 4.12 g cm 3 is suspended in water at 33°C. At this temperature, the density and viscosity of water are 0.9947 g cm-3 and 7.523 10-3 P, respectively. A particle size analyzer (SediGraph, Micromeritics Instruments Corp., Norcross, GA 30093) plots the following data for cumulative weight percent versus equivalent spherical radius ... 

The distance-time combination corresponding to this weight percent is determined by the particle size analyzer and converted to Rs. ... 

A typical feed composition was 1000 g capsul, 2334 g deionized water and 200 g orange oil. The finished powders were stored in amber bottles at -25prior to accelerated storage study and relevant analyses. Particle Size Analysis. To ascertain the effect of atomizer voltage on the particle size, the particle size distributions of three powders were first determined. The Microtrac laser light particle size analyzer (Medallion Laboratories, Minneapolis, MN) was used in this study. The volume percent data over particle diameter ranging 2.8 p. to 176 jii was recorded. Mean value of the volume percent distribution and calculated surface area were also obtained. 

Particle size distribution (oil droplets) using a light scattering technique was measured on a Leeds and Northrop Microtrak particle size analyzer as described by Weiss and Frock (18). Replicate samples of the encapsulated products were dissolved in water. The beta-cyclodextrin sample was only partially soluble therefore, the insolubles were allowed to separate out before removing the supernatent for evaluation. 

Table V gives the combined means of the differences between duplicate trace element determinations for each coal particle size analyzed. Both the means of the absolute differences (in ppm) and the means of...

Method of analysis (Re-Tap sieve shaker, SediGraph particle size analyzer, or other equipment) ... 

Particle size distributions of the reactant as well as of the product powders, were measured by a HORIBA (model CAPA-700) particle size analyzer. This instrument uses a non-contact method based on liquid-phase sedimentation, and has a measuring range between 0.01 and 300 pm. 

CLS13 320 Particle Size Analyzer (Beckman-Coulter Co.), by volume-weight... 

LS Particle Size Analyzer, Beckman Coulter, 27 March 2002, MC 195-OOP.O. Box 169015 Miami, Florida 33116-9015. 

Particle Size Analysis. Particle size distribution measurements of the dry resin were made using a Micromeritics Sedigraph 5000D particle size analyzer. This instrument employs a gravity settling technique and uses Stokes law to determine the particle size. The PSD was run over the size range of 0.36 to 100 micrometers. All measurements were made in dibutyl sebacate as the suspending medium. 

Commercially available particle size analyzers will typically report particle size data as mass distributions and assume that particle geometry is spherical. Particles that are similar in size will be grouped and represented by an average particle size for the range or the range may be specified. For the sake of space efficiency,... 

The disc centrifuge used in this study has been described previously (4, 5). (A commercial verlson of the instrument is now available from Brookhaven Instruments Corporation, Ronkonkoma, NY, as the Brook-haven DCP-1000 Particle Size Analyzer.) The latexes used in this study are monodisperse Dow polystyrene latex standards covering a range of sizes and two commercial latexes designated as 2 and 4, both of which had a broader dispersity than the polystyrene latex standards. All of the latex sample preparations analyzed in the statistical study were prepared in a similar manner. All the fluids were held in a thermostatically controlled temperature bath at 25°C. The temperatures at the beginning and end of each run were recorded. 

The DCP used was a variable speed unit developed in our own laboratory (3-6). (A commercial version of this instrument is mow available as the Brookhaven DCP-1000 Particle Size Analyzer from Brookhaven Instruments Corporation, Ronkonkoma New York. SFFF measurements were performed using a prototype instrument provided by DuPont (.] ) (A commercial version of this instrument is now available as the DuPont SFFF-1000 Particle Size Analyzer.) HDC measurements were made by Micromeritics on their Model HDC-5600 Flowsizer instrument. QELS measurements were made on an instrument constructed by Professor Alex Jamieson at Case Western Reserve University (8). TEM measurements were made by the Pigments Division of SCM Corporation, Adrian Joyce Plant, Baltimore, Maryland. Turbidity measurements were made using a Bausch and Lomb Model Spectronic-20 spectrometer. 

FIG. 5 Transformation of the information in Fig. 4 to volume concentrations as is typically measured by modern particle size analyzers (fractal dimension assumed to be 1.6). 

The model solutions discussed above were compared with experimental data collected using a laser diffraction particle size analyzer. Hematite was dispersed in solutions at various pH values and moderate ionic strength (0.02 M) such that aggregation rates varied from slow to fast, and aggregation was allowed to occur in quiescent solution. The aggregating dispersion was sampled over time, and data was represented in three dimensions as the change in particle size distributions over time. Figure 10a shows hematite... 

---